1. Field of the Invention
The present invention relates to a non-volatile memory device, and more particularly, to a non-volatile memory device that can repetitively perform data write/erase operations in an embedded semiconductor device.
2. Description of the Related Art
As the use of digital devices increases, the use of non-volatile memory devices is also increasing. The non-volatile memory devices can repetitively perform data write/erase operations.
An embedded semiconductor device having the non-volatile memory function is a device in which a memory device and a logic circuit for driving the memory device are implemented in a single chip. That is, the embedded semiconductor device is fabricated using the combination of a logic semiconductor fabrication technology and a non-volatile memory fabrication technology.
FIG. 1 is a cross-sectional view of a memory cell structure of a conventional non-volatile memory device.
Referring to FIG. 1, the conventional non-volatile memory device includes a first insulating layer 20 on a semiconductor substrate 10. A floating electrode 30 is formed on the first insulating layer 20 acting as a tunneling oxide layer. A second insulating layer 40 is formed on the floating electrode 30 and a control electrode 50 is formed on the second insulating layer 40.
When the conventional non-volatile memory device having a stack gate type memory cell structure with the dual gate structure is used as a non-volatile memory device of an embedded semiconductor device, additional processes as well as a logic circuit process are required to form non-volatile memory cells. The additional processes include a process of forming the tunneling oxide layer 20, a process of forming the floating electrode 30, and a process of forming the second insulating layer 40 and the control electrode 50 on the floating electrode 30. Thus, the conventional non-volatile memory device has problems in that a manufacturing process becomes complex and a manufacturing cost increases.
As the degree of integration increases, the stack type non-volatile memory cells are widely used. In this case, because the topology excessively increases, the planarization becomes difficult in a following process and the process difficulty further increases.